Mix together sourdough and water. Note water temperature for later in the recipe.
Mix together flour, salt, and sugar in a separate bowl; then add starter; mix well to combine.
Allow dough to rest for 8-10 hours; if the water was below 70°F when added to the starter, stretch the rest time to 10 hours. For temps above 70, it can be ready in 8 hours.
The dough will be loose, but turn out onto a clean surface. You may add flour to the surface if desired. Divide into two equal portions.
Preheat oven to 450°F and line a baking sheet with parchment paper.
Start to shape the dough into long strips, until the surface is smooth. You can do this by pushing and pulling the dough back and forth. Using a bench scraper is helpful. Let the dough rest for 15-20 minutes.
Stretch the dough into longer pieces, about 18-20” long. Coat in olive oil and transfer to a baking sheet. Generously salt each baguette. The dough is loose, but that’s okay! You can score the dough now or a few minutes into baking.
Bake in a preheated oven for 15-20 minutes until golden brown.
Let cool before cutting.
Notes
I recommend eating within a few days. It's perfect for sharing too, like if you're making lasagna for you and a neighbor you can easily toss a loaf of this with it.